Police wrap up De Pere murder-suicide investigation

Order to move out suspected as the cause

Feb. 23, 2012

DE PERE — Denis Bay's wife was throwing him out of the house the day he shot and killed her and their two children before turning the gun on himself, police said Wednesday.

Police Chief Derek Beiderwieden said long-running marital troubles were a primary source of stress leading up to the Feb. 3 murder-suicide that left the four family members dead in their home.

Although investigators cannot pinpoint Bay's exact motive, Beiderwieden said, his wife's decision to kick him out of the house appears to be "the trigger."

"When you piece it all together, it kind of makes sense," the chief said. "That was the day he was supposed to leave."

The couple was going through a divorce after nearly 20 years of marriage.

De Pere police are wrapping up their investigation into this month's incident at 1245 S. Erie St. in which Bay, 46, killed his wife, Michelle, 44, their daughter, Andrea, 14, and their son, Daniel, 10, before turning the gun on himself.

The Rev. Matthew Knapp, a family spokesman, said Wednesday that none of the surviving family members wanted to comment on the police findings.

Sgt. Thomas Schrank, head of the police department's detective bureau, said investigators were able to interview family members and others in an effort to piece together the circumstances surrounding the murder-suicide.

It was De Pere's first homicide since 2004 and possibly the city's first murder with multiple victims.

"We tried to gather as much of the facts as we could," Schrank said. "We got great cooperation from everybody."

Family members, friends and neighbors told police that Denis and Michelle Bay long struggled with a rocky marriage.

Michelle Bay filed for divorce in October 2010 and moved out of the home with both children. But she moved back by the following summer, and the couple agreed to spend another six months trying to work out their problems.

Other factors causing stress for the family included the loss of Denis Bay's job in March 2011, as well as Michelle Bay's chronic back pain, and the wife's "hoarding" habit that filled the family's house with clutter, according to police.

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"There were a number of stressors," the chief said.

Police are unsure when Michelle told Denis that she wanted him to move out, but the move was supposed to occur on Feb. 3.

The couple agreed that Denis could say goodbye to the children first, so Michelle called the schools about 1:45 p.m. to report that her husband would pick the kids up early. Andrea was a freshman at De Pere High School, and Daniel was a fourth-grader at Heritage Elementary School.

Beiderwieden said surveillance video shows that Denis stopped at a favorite nearby convenience store to purchase a soda and a cigar on his way to the schools.

Employees at Heritage school told investigators that Denis was pacing and appeared anxious in the school office.

While Denis picked up the kids, Michelle called one of her sisters in Door County about 2:30 p.m. and announced that she was making Denis move out of the house that day.

The sister expressed concern about violence, but Michelle offered assurances that Andrea had tried to hide either Denis' gun or ammunition — the sister could not remember which.

The murder weapon was a .45-caliber handgun that Michelle had purchased for Denis as a gift three years earlier.